Method and system for stacking and feeding workpieces of limp material

ABSTRACT

A method and system are disclosed for stacking and feeding workpieces of limp material onto and from conveyable worktables by angularly displacing the successive workpieces in the stack to provide a stable stack in which the individual workpieces retain their oriented positions, accommodating nonuniform thickness or contour. The limp material is such as fabric, cloth, leather, plastic or any other limp material, and the invention is advantageous for use in the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like. The identity of the individual workpiece in the stack as well as the identity of the stack itself is preserved. Workpieces having sections of differing thickness or contour are accommodated by utilizing predetermined angular increments of displacement between the stacking or feeding of respective successive workpieces on the conveyable worktables to provide stacks of workpieces which may take any one of several forms as described. The invention also facilitates the differentiation of the top workpiece from the stack without disturbing the remaining ones.

tates Patent [72] Inventor Herman llovin Not-walk, Conn. 2| Appl. No. 858,013 [22] Filed Sept. 15, 1969 [45] Patented Aug. 24, 1971 [73] Assignee Ivanhoe Research Corporation New York, N.Y.

[54] METHOD AND SYSTEM FOR STACKING AND FEEDING WORKPIECES 0F LIMP MATERIAL 10 Claims, 7 Drawing Fig.

[52] US. Cl 27l/86, 271/74 [5 l 1 Int. Cl B65h 29/32 [50] Field ofSeaa-ch 271/86, 3, l, 26, 74, 84

[56] References Cited UNITED STATES PATENTS 2,172,519 9/1939 Reeder 271/62 2,654,369 10/1953 Van Buul.... 27l/26X 2,683,601 7/1954 Camerano 27 1/86 3,442,505 5/1969 Szentkuti Primary Examiner-Joseph Wegbreit An0rneyBryan, Parmelee, Johnson & Bollinger ABSTRACT: A method and system are disclosed for stacking and feeding workpieces of limp material onto and from conveyable worktables by angularly displacing the successive workpieces in the stack to provide a stable stack in which the individual workpieces retain their oriented positions, accommodating nonuniform thickness or contour. The limp material is such as fabric, cloth, leather, plastic or any other limp material, and the invention is advantageous for use in the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like. The identity of the individual workpiece in the stack as well as the identity of the stack itself is preserved. workpieces having sections of differing thickness or contour are accommodated by utilizing predetermined angular increments of displacement between the stacking or feeding of respective successive workpieces on the conveyable worktables to provide stacks of workpieces which may take any one of several forms as described. The invention also facilitates the differentiation of the top workpiece from the stack without disturbing the remaining ones.

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I m-ro nzvs METHOD AND SYSTEM F OR STACKING AND FEEDING WOlRlKlPIECES OF LllMlP MATERIAL DESCRIPTION The present invention relates to a method and system for handling quantities of limp material workpieces in an orderly manner. More particularly, the present invention relates to a method and system for handling limp material, such as fabric, cloth, leather, plastic or any other limp material whether natural or unnatural or a combination thereof, where workpieces are processed individually but are conveyed in orderly quantities, as in stacks or bundles, and the identity of the stack and the identity of the individual workpiece forming the stack are preserved.

In the manufacture of garments and/or wearing apparel, headgear, footwear, home furnishings, large quantities of panels or workpieces of identical pattern or shape are used. The pattern parts or panels are normally cut from material which has previously been laid out in a plurality of layers-and the cut panels or workpieces are presented in stacks or bundles, each of which (both workpiece and stack) have particular identity. During the manufacturing process it is most desirable to preserve both the identity of the individual identi-. ty. During the manufacturing process it is most desirable to preserve both the identity of the individual workpieces in the stack as well as the identity of the stack itself, because this assures that the completed garment or other product will be assembled from workpieces of desired conforming characteristics, such as color shading. The workpieces are conveyed from place to place in stacks or bundles and are individually separated from the stack for presentation to the workpoint, each workpiece in the stack being worked upon individually. During the manufacturing process some individual workpieces are combined with other individual workpieces forming a composite workpiece for use during other subsequent steps. A

workpiece" may be an individual workpiece or a composite workpiece; it may be a piece of material on which no work has been performed; or it may be fastened, hemmed, or seamed, or otherwise having been worked upon. After having work performed thereon, the workpiece is returned to a position where workpieces are stacked for further conveyance.

The identity of the stack is established when a plurality of layers of material are laid up and initially cut in predetermined pattern thereby forming a stack of workpieces. The identity of each workpiece in the stack is important because there may be subtle variations or gradations in color or other characteristics occurring in the material being cut. Therefore, it is important to handle the respective workpieces in each stack in predetermined order to assure that the product, such as a garment, is assembled from workpieces, whose characteristics are as nearly identical as possible.

By treating each stack as a separate entity, the identity of the stack is automatically preserved. This makes possible preservation of the identity of the individual workpieces making up the stack; also this identity continues when workpieces from different stacks are combined to form a composite workpiece and may thereafter be stacked, thereby forming a stack of composite workpieces.

The identity of the stack is preserved by initially placing the stack on a conveyable worktable, removing the stack from the worktable in a manner so as to preserve the identity of the workpieces of the stack and reforming the stack on another (or the same) worktable. Conveyable worktables are described in copending patent application, Ser. No. 681,267, filed on Nov. 7, 1967, by George F. Hawley, said application being owned together with the present application. Such conveyable worktables are referred to therein as transportable interchangeable coordinating worktables."

Problems in forming stacks of workpieces on conveyable or transportable worktables and in preserving the proper orientation of the respective workpieces in the stack on the worktables arise when the workpiece is a composite workpiece or the workpiece has a nonuniform thickness or the size or contour of the workpiece is such as to create an uneven or unstable stack or a loss of space on the worktable on which the stack is placed. I

The present invention overcomes these problems by generating stacks which are stable and wherein the individual workpieces retain their oriented location or positions in the stackregardless of their nonuniform thickness or contour.

Moreover, the present invention enables each individual workpiece to be separated or differentiated readily from its neighbors in the stack in a manner to assure that only one workpiece at a time is separated and delivered during the delivery stroke and without displacing any of the remaining workpieces in the stack. workpieces of limp material such as described above are difficult to be differentiated one from another when in a congruent stack.

Differentiating is the act of separating or removing a workpiece, one at a time, from a stack of workpieces. Ideally, ap-

paratus for differentiating selectively removes the exterior one, (normally the top workpiece in the stack) from a stack of workpieces without disturbing the other workpieces in the stack.

The present novel material-handling method and system provides apparatus for handling a wide variety of stacks of workpiece in which the transportable worktables are angularly displaced by pred etermined angular increments between the stacking or feeding of respective successive workpieces and thereby generate variations in the style or form of the stack so made so that the system accommodates a wide variety of stacks of workpieces where the size and pattern of the workpieces differ from those when originally introduced in the system, and the nature and contour of the workpieces change during the manufacturing process.

One or more stacks of workpieces are placed on individual conveyableworktables which serve to present each individual workpiece, in sequence in predetermined coordinate location and predetermined orientation. The conveyable worktable may be placed on a conveyoralong which it moves or is moved or conveyed from one place to another in predetermined arrangement. Initially, stacks of workpieces are placed on these worktables and the individual workpieces of the stack are removed from the stack and individually processed. The processed workpiece may be deposited or placed on another transportable worktable thereby developing or forming other stacks of workpieces. The orientation of eachworkpiece, with respect to its position in the newly formed stack may be inverted.

The angular displacement of the conveyable worktables between the depositing of respective successive workpieces can be used to advantage to generate stacks of workpieces which may take any one of several forms. The form of the stack so generated is a function of the increment of angular displacement of the worktable between deposits of workpieces in forming the stack, for example the respective workpieces of the generated stack may partially overlap part of another workpiece in the stack at a substantially corresponding level in the respective stack. This stack arrangement provides a very stable stack and assures that each workpiece remains in its predetermined oriented coordinate location.

In order to achieve or form various configurations of stacks during the stacking process and in order to remove the workpieces from the various configuration of stacks during the feeding process, the worktable which supports the stack or stacks is precisely positioned in the X and Y direction and rotationally and vertically oriented. Apparatus for angularly displacing the respective worktables is described below.

Thus it will be seen that in using the novel method and system for handling quantities of material, a wide variation in types and forms of stacks can be generated to accommodate many different types and sizes of workpieces,

When feeding workpieces into a workstation using a worktable carrying a type or form of stack which has been generated by angular displacement of the workable during stacking the worktable is precisely positioned in X and Y directions, in elevation and in rotational orientation and the worktable is angularly displaced by a predetermined angular increment after each successive top workpiece is removed so that the next successive top workpiece is in position to be removed.

When generating or feeding into orfrom a fan stack, rotation of the worktable may be carried out in relativelysmall uniformpredetermined increments which may be used to advantage when processing certain types of composite workpiece.

The various objects, aspects and advantages of the present invention will be more fully understood from a consideration of the following description in conjunction with the accompanying drawings, in which:

FIG. 1 is an expanded perspective view illustrating the angular displacement of each workpiece with respect to the other workpieces that are to be stacked or fed, as the case may be;

FIG. 2 is a plan view showing the workpieces arranged in one form of stack;

FIG. 3 shows the feeding and stacking of the workpieces achieved by angular displacement of the worktable;

FIG. 4 shows apparatus which is capable of stacking workpieces in accordance with the disclosed method;

FIG. 5 shows apparatus which is capable of feeding the workpiece in accordance with the disclosed method;

FIG. 6 illustrates a system in which the workpieces are arranged in a fanlike stack; and

FIG. 7 shows the stacking of the long workpieces which are folded to reduce their effective size in accordance with the disclosed method.

This invention relates to a method and apparatus for handling quantities of limp material which is to be stacked on individually conveyable worktables in such a manner as to create a stable stack wherein the identity of the individual workpiece as well as that of the stack itself is maintained. This is accomplished by stacking and feeding the workpieces so that each workpiece is displaced a predetermined angular increment with respect to the preceding workpiece. FIGS. 1 and 2 show the method of stacking the workpieces in greater detail. workpieces l1, 12, 13, and 14 are each composed of a section A which is of a thicker section than section B, i.e. there are more plies in section A. Arrows 4 and 5 illustrate relative motion for stacking and feeding operations, respectively, on worktable 20.

The workpieces are stacked so that respective areas of greater thickness of one workpiece are generally matched with and placed in overlapping relationship with areas of lesser thickness of preceding workpieces. Thus, when the workpieces are located 180 apart (asis the case with workpieces 11 and 13 and also with workpieces 12 and 14) then in looking down the perimeter of the stack, one would see alternately, workpieces of thicker cross section and of thinner cross section, etc. The stack 22 in the present example is composed of successive workpieces angularly displaced 90 with respect to one another, utilizing the. principle as discussed above, i.e. arranging the workpieces so that areas of greater thickness are matched with and placed in overlapping relationship with areas of lesser thickness of preceding workpieces.

More particularly. the workpieces 11, 12, 13 and 14 are stacked about the centerline 24 of worktable in angular increments of 90 with respect to one another. The result is that workpieces II and 13 are rotated l80 with respect to one another and similarly workpieces 12 and 14 are rotated 180 with respect to one another. The thicker section of workpiece I1 is thus oriented in the stack so that it is overlapped by the thinner section of workpiece 13. Likewise, the thinner section of workpiece 11 is oriented in the stack so thatit is overlapped by the thicker section ofworkpiece 13. workpieces 12 and 14 are oriented in a similar manner, but they are respectively displaced 90 with respect to the preceding workpieces 11 and l3.

FIG. 2 shows the completed tack formed in the manner shown in FIG. 1 and above described. The feeding operation, that is the operation whereby the workpieces are removed from the stack is the inverse of the stacking operation, workpiece 14 first being removed, followed by workpiece 13, I2 and 11, respectively.

The stacking operation as described above is advantageously accomplished by indexing the worktable a predeterminedangular increment after each workpiece is placed thereon. Rotating the worktable allows the material to be stacked form a single position in the XY plane yet achieve the desired result of stacking the workpieces in such a way as to be angularly displaced with respect to one another.

FIG. 3 provides an illustration of the stacking and feeding operations carried out by rotating the worktable a predetermined angular increment after each piece has been placed thereon. Workpiece 11 is placed on the worktable 20 from a stacking station (such as shown in FIG. 4) which is aligned in a permanent XY relationship with the centerline of the worktable 20. The worktable is rotated through an angular increment of Workpiece 12 is then placed on the worktable by the stacking station in exactly the same XY relationship with the centerline of the worktable as was workpiece 11. Worktable 20 is again rotated through an angular increment of 90, as shown by the solid-headed arrow to the next position. Workpiece 13 is placed on the worktable by the stacking station in exactly the same XY relationship with the centerline of the worktable as were workpieces 11 and 12. Worktable 20 is again rotated through an angular increment of 90 as shown by the solid headed arrow, and workpiece 14 is placed on the worktable in exactly the same XY relationship with the centerline of the worktable as were the workpieces 11, 12, and 13.

The feeding operation is the inverse of the stacking operation as indicated by the open-headed arrows. The worktable 20 is brought to a feeding station (such as shown in FIG. 5) which is permanently aligned in the XY plane with the centerline of the worktable. The feeding station removes the successive workpieces in the inverse procedure as shown by the open-headed arrows. After the workpiece 14 has been removed, the worktable 20 is rotated, as shown by the openheaded arrow, through an angular increment of 90. Workpiece 13 is now aligned with the feeding station and is removed. worktable 20 is again rotated through an angular in crement of 90 as shown by the open-headed arrow and workpiece 12 is removed, and so forth.

FIGS. 4 and 5 show in detail a system for carrying out the methods which are discussed above. FIG. 4 discloses an illustrative stacking operation. A conveyor belt 16 delivers the workpieces placed thereon to the stacking station 17. A suction pickup unit 18 is connected by a flexible hose 19 to a suction source and serves to remove the workpieces from the conveyor 16 to place them on the worktable 20.

The suction unit 18 is movably mounted in a support bracket 22 and is suitably driven back and forth, as indicated by the arrow 23, and is driven up and down, as indicated by the arrow 24. Suitable drive mechanism for providing such motions is described in detail in US. Pat. No. 3,442,505, which issued May 6, 1969. The suction unit 18 includes a plurality of inverted suction cups 25, including wire bristle friction means such as those described in that patent. The workpieces 26 are removed from the conveyor belt by engaging the suction cups 25 with the workpiece, while the suction is applied, and they are delivered onto the worktable 20 by removing the suction to release the workpiece.

The worktable 20 is held by a table support including arms 28 attached to a rotatable shaft 30. An electric stepping motor 35 which is capable of accurately rotating the worktable 20 through a predetermined angle of rotation is coupled to shaft 30 through gears 36 and 37.

The table support has a hub 29 and holds the worktable 20 which was obtained by the operator from a suitable supply rack 38. After worktable 20 has been fully stacked with workthe conveyor 40.

pieces, it is removed from the worktable support 28, 29 and is placed on a conveyor 40 which removes the stacked worktables away from the stacking station 117.

The operation of the stacking station is'as follows: Worktable is removed from the rack 38 and is placed on the workable support 28, 29. Conveyor belt 16 brings workpieces 26 to the stacking station 17 where each individual workpiece is removed by the pickup unit 18 and is transferred to the worktable 20. Suction provided by suction means 19 is applied to the suction cups to enable the pickup unit 18 to hold the workpiece. When the pickup unit 18 is brought over adjacent to the worktable 20 the suction is momentarily interrupted thereby releasing the workpiece to remain in the desired position on the worktable. The pickup unit 18 is returned adjacent to the conveyor belt, and the motor 35 rotates the worktable 20 through an angular increment of 90. The operation of the stacking station is continued until a completed stack 41 has been formed. The worktable is then removed from the worktable support and is carried away from the stacking station on The workpieces 26 are relatively long and narrow. By virtue of the stacking operation as described, a stable stack 41 is provided. Moreover, the arrangement of the stack 41 facilitates the subsequent feeding of successive workpieces, as will be described in connection with FIG. 5.

The feeding station 17A, as shown in FIG. 5, is generally similar to the stacking station 17. Stacks 41 which are composed of long rectangular workpieces interlaced with one another attheir ends so as to form a square with an open center are transported on a conveyor 42 to the feeding station area. The feeding station 17A includes a pickup unit 18 having suction cups 25 for the removal and transfer of the workpieces 16 from the stack 41 and includes an inverter mechanism 44 which accepts the workpieces from the pickup unit 18 and transfers them onto a conveyor belt 46.

The operation of the feeding station 17A is as follows: worktables 20 with stacks 41 deposited thereon, are transported by conveyor 42 to the feeding station area. There pickup unit 18 removes each workpiece from the stack, a stepping motor and gears 36 and 37 rotate the stack and worktable through the same angular increment of 90, but in a direction opposite to that which was used in the stacking operation, thus having the effect of unwinding the respective workpieces from interlaced relation in the stack. A retainer clamp 48 is capable of'moving up and down and has a plurality of feet 49 which serve to apply slight pressure to the two workpieces 51 and 52 located in contact with the ends of the workpiece 26 being removed from the stack. This retainer clamp thereby prevents workpieces 51 and 52' from beingdisplaced in the stack 41 along with the workpiece 26. Workpiece 26 is then placed on inverter means 44 which transfers the workpiece to the conveyor belt 46. When the pickup unit 18 carrying workpiece 26 is located adjacent to the inverter 44, the suction is momentarily interrupted thereby releasing the workpiece onto the inverter 44. This inverter 44 includes a plurality of suction ports for holding the workpiece while the inverter swings over to its alternative position 44', at which position the suction is turned off to release the workpiece onto the conveyor 46. After the workpieces composing stack 41 have all been removed by the feeding operation, the empty worktable is placed with other worktables on a rack 54.

It is noted that the worktables 20 have a plurality of alignment detents 56 for cooperative engagement with the indexing support 28, 29. These detents are registration holes which are engaged by upright registration pins 58 (FIG. 4) at the ends of the respective arms 28. A central hole 57 may be provided for engagement with a central pin on the hub 29.

In the stacking station 17 and in the feeding station 17A the shaft 30. which is connected to the worktable support 28, 29, can be moved up and down. This shaft extends through the hub of the gear 37 and is slidably splined to this hub to permit the shaft 30 to be moved up and down to elevate or lower the worktable. Elevating means (not shown) is connected to the lowerend of this shaft 30 for raising and'lowering it; for example, a vertical feedscrew and an electrical motor driven feednut may be used.

The angular displacement of the coiiveyable worktables between the depositing of the successive workpieces can be used to advantage to generate stacks of workpieces which may take any one of several forms. The form of the stack so generated is a function of the increment of angular displacement of the worktable between deposition of the successive workpieces thereon. When generating or feeding from a fan stack 60, as shown in FIG. 6, rotation of the worktable is carried out in relatively small uniform, predetermined increments. FIG. 6 shows a feeding operation from a fan stack carried out in a system which is similar to that as described in FIG. 5. The important difference is that the worktable is rotated through a much smaller angular increment each time that a workpiece is removed.

The small angular increment is sufficient to cause an area 62 lying along a radial edge of the exposed workpiece 64 tov rest directly upon the worktable 20A with no workpiece overlapped beneath it. Thus, suction can be applied to the narrow edge area 62 without disturbing the other workpieces iri the fan stack 60. The suction pickup unit 18 in the feeding station 178 includes an elongated suction head 25A which is shaped to conform generally to the nonoverlapping area 62. In this way suction can be used to remove porous workpieces, such as garment fabric pieces, one at a time from a stack without disturbing any other workpiece in the stack. The head 25A is moved down near to the conveyor belt 46, and the suction is interrupted to release the individual workpiece 66 onto the conveyor 46.

When all of the workpieces have been removed from the worktable in the feeding station 178, the shaft 30 is lowered until the empty worktable 20A rests upon the rails 67 and 68. An ejector mechanism in the form of a pneumatic cylinder and pushrod (not shown) serves to push the empty worktable 20A down a pair of chute rails 69 and 70.

The next worktable, which carries a fanstack 60 is slid along the conveyor rails 67 and 68 into position to be engaged by the support 28, 29 which is then elevated by the shaft 30. The worktable 20A is similar to that shown in FIGS. 4 and 5, except that the detents 56A are notches in its perimeter, which are engaged by the registration pins 58, The central opening 57 of the respective worktables may have distinctive shapes, as shown in FIG. 6, for distinguishing the respective worktables from each other.

In the system of FIG. 6, a retainer clamp such as that shown at 48, 49 in FIG. 5 may be used if desired to restrain the next workpiece 65 when the top workpiece 64 is being removed. This retainer clamp is positioned to engage down upon the exposed portion of the workpiece 65.

FIG. 7 shows the stacking of large workpieces on the worktable 20 by prefolding the workpiece to reduce its effective length. A leg panel workpiece 74 which has been folded over so as to consume less working area and for ease of handling is moved from a supply station over into the worktable 20. Thereafter, the worktable 20 is rotated through an angle of and a second workpiece 76 is placed onto the worktable, as shown at 76'. The worktable is again rotated through an angle of 90 and a third workpiece 78 is deposited on thetable, as shown at 78. It will be noted that each leg panel workpiece is aligned with respect to the other workpieces so as to. form a stable stack. The transfer of the prefolded leg panels 74, 76 and 78 is accomplished by using a large area suction head 25B to which sufficient suction is applied to pick up both layers of the prefolded workpiece, The prefolded workpieces are delivered one at a time to the supply station 80 by means of a conveyor belt 82.

In forming the stack 41 and the stack 60 the respective workpieces are placed onto the worktable offset from the centerline 24 (FIG. 1), thus providing an open central region as shown in FIGS. 4, 5 and 6.

What is claimed is:

. individually engaging and rotating said worktable through registering an individually transportable flat surfaced worktable into position at a stacking station; placing a first workpiece onto the worktable;

a predetermined angular increment solely about the vertical axis of said transportable worktable;

. placing a second workpieceonto the worktable wherein the second workpiece is placed in partial overlapping relationship with the first workpiece and is placed on the worktable in the same spacial relationship with the vertical axis of the worktable as was the first workpiece when it was placed on the table;

again individually rotating the worktable through another predetermined angular increment solely about its vertical axis the same as with the first workpiece;

. placing a third workpiece onto the worktable wherein the third workpiece is placed in partial overlapping relationship with the second workpiece and is placed on the worktable in the same spacial relationship with the said vertical axis of the worktable as were the first and second workpieces when they were placed on the worktable;

individually rotating the worktable through the same predetermined angular increment solely about its vertical axis the same as with the first and second workpieces;

repeating the operation with subsequent workpieces, whereby the workpieces in the stack become arranged in partially overlapping and interlacing relationship to provide mutuality of support for the workpieces and thereby providinga stable stack; and,

individually moving "the worktable carrying the stable stack to another location.

In the manufacture of garments, wearing apparel,

headgear, footwear, home furnishings, and the like, the method of feeding individual workpieces from a stable stack as formed by the method of claim 1 comprising the steps of:

in. rotating the worktable through the same predetermined registering the worktable carrying the stable stack at a feeding station;

. removing from the stack the top and last workpiece to have been placed on the stack;

. rotating the worktable through the same predetermined angular increment solely about the vertical axis of'the worktable as was done in forming the stack but in a direction which is opposite;

. removing from the stack the second to last workpiece to have been placed thereon which is now located on the top of the stack;

angular increment solely about the vertical axis of the worktable as was done in step (k) above; and

repeating the steps with the remaining workpieces in the stack for individually removing them while preserving their individual identity and orientation.

The feeding method of claim 2 including the additional step of:

removing each workpiece by applying the removal force to an exposed region thereof which is in nonoverlapping relationship with the next successive workpiece in the stack.

The method of forming a stable stack from a plurality of The method of forming a stable stack from a plurality of identical limp workpieces wherein the identity of the individual workpieces as well as the identity of the stack itself are preserved and wherein the cross-sectional thickness at least one region of the respective workpieces differs from that in another region thereof, such method comprising the steps of:

a. registering an individually transportable flat surfaced worktable into position at a stacking station;

. placing a first of the workpieces onto the worktable;

. rotating the worktable through a predetermined angular increment solely about the vertical axis of the worktable; d. placing a second of the workpieces onto the worktable, wherein the second workpiece is arranged with respect to a first so that a thinner region of one of them overlaps a thicker region of the other;

. the second workpiece being placed on the worktable in the same spacial orientation with the vertical axis of the worktable as was the first workpiece when it was placed thereon;

f. rotating the worktable through the same predetermined angular increment solely about its vertical axis as before;

g. placing a third of the workpieces onto the worktable wherein the third workpiece is arranged with respect to the second so that a thinner region of one of the latter of the two workpieces overlaps a thicker region of the other;

h. the third workpiece being placed on the worktable in the same spacial orientation with the vertical axis of the worktable as were the first and second workpieces when they were respectively placed on the worktable;

i. rotating the worktable through the same predetermined angular increment solely about its vertical axis as before;

j. repeating the steps with subsequent workpieces; and

k. individually moving the worktable carrying the stable stack to a feeding station. 6. A method for forming a stable stack from a plurality of identical limp material workpieces wherein the identity of the individual workpieces as well as the identity of the stack itself is preserved, such method comprising the steps of:

a. positionally registering an individually transportable worktable and a stacking station relative to one another;

b. placing a first of the pieces onto the worktable;

c. moving the worktable and a stacking station in relation to one another through a predetermined angular increment solely about the vertical axis of the worktable;

d. placing a second of the workpieces onto the worktable wherein the second workpiece is arranged in partial overlapping relationship with the first workpiece;

e. moving the table and stacking station in relation to one another through the same predetermined angular increment solely about the vertical axis of the worktable;

. placing a third of the workpieces onto the worktable wherein the third workpiece is placed in partial overlapping relationship with the second workpiece;

g. repeating the steps for subsequent workpieces to provide a stable stack in which the workpieces are arranged in partial overlapping and interlacing relationship to provide mutuality of support for the workpieces and thereby provide a stable stack; and

h. individually displacing the worktable carrying the stable stack relative to the stacking station so that the worktable is situated at another station,

7. The method for forming a stable stack of limp workpieces as claimed in claim 6 in which;

i. the respective workpieces are placed onto the worktable in offset relationship with respect to the axis of the worktable; and

j. the predetermined angular increment through which the worktable and feeding station are moved in relation to one another provides a fan stacking relationship. 8. A system for use in the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like, in which a plurality of identical workpieces of limp material are utilized comprising:

a. an individually transportable worktable for carrying a stack of the workpieces;

b. a worktable support for individually engaging the worktable to support it; p

c. indexing drive means for indexing the worktable through a sequence of predetermined angular increments solely about a vertical axis passing through the worktable;

d. delivery means for delivering the workpieces;

e. pickup means for placing the respective workpieces onto the worktable in the same predetermined orientation with respect to the vertical axis preceding each indexing movement of the worktable to generate a stack of overlapping, interlaced workpieces;

f. means for individually moving the worktable from one location to another. 

1. In the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like, the method of forming a stable stack from a plurality of identical limp material workpieces wherein the identity of the individual workpieces as well as the identity of the stack itself is preserved, comprising the steps of: a. registering an individually transportable flat surfaced worktable into position at a stacking station; b. placing a first workpiece onto the worktable; c. individually engaging and rotating said worktable through a predetermined angular increment solely about the vertical axis of said transportable worktable; d. placing a second workpiece onto the worktable wherein the second workpiece is placed in partial overlapping relationship with the first workpiece and is placed on the worktable in the same spacial relationship with the vertical axis of the worktable as was the first workpiece when it was placed on the table; e. again individually rotating the worktable through another predetermined angular increment solely about its vertical axis the same as with the first workpiece; f. placing a third workpiece onto the worktable wherein the third workpiece is placed in partial overlapping relationship with the second workpiece and is placeD on the worktable in the same spacial relationship with the said vertical axis of the worktable as were the first and second workpieces when they were placed on the worktable; g. individually rotating the worktable through the same predetermined angular increment solely about its vertical axis the same as with the first and second workpieces; h. repeating the operation with subsequent workpieces, whereby the workpieces in the stack become arranged in partially overlapping and interlacing relationship to provide mutuality of support for the workpieces and thereby providing a stable stack; and, i. individually moving the worktable carrying the stable stack to another location.
 2. In the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like, the method of feeding individual workpieces from a stable stack as formed by the method of claim 1 comprising the steps of: i. registering the worktable carrying the stable stack at a feeding station; j. removing from the stack the top and last workpiece to have been placed on the stack; k. rotating the worktable through the same predetermined angular increment solely about the vertical axis of the worktable as was done in forming the stack but in a direction which is opposite; l. removing from the stack the second to last workpiece to have been placed thereon which is now located on the top of the stack; m. rotating the worktable through the same predetermined angular increment solely about the vertical axis of the worktable as was done in step (k) above; and n. repeating the steps with the remaining workpieces in the stack for individually removing them while preserving their individual identity and orientation.
 3. The feeding method of claim 2 including the additional step of: n. removing each workpiece by applying the removal force to an exposed region thereof which is in nonoverlapping relationship with the next successive workpiece in the stack.
 4. The method of forming a stable stack from a plurality of identical limp material workpieces wherein the identity of the individual workpiece as well as the identity of the stack itself is preserved according to claim 1 wherein the workpieces are leg panels which have been folded to reduce their effective lengths prior to placement on the worktable.
 5. The method of forming a stable stack from a plurality of identical limp workpieces wherein the identity of the individual workpieces as well as the identity of the stack itself are preserved and wherein the cross-sectional thickness at least one region of the respective workpieces differs from that in another region thereof, such method comprising the steps of: a. registering an individually transportable flat surfaced worktable into position at a stacking station; b. placing a first of the workpieces onto the worktable; c. rotating the worktable through a predetermined angular increment solely about the vertical axis of the worktable; d. placing a second of the workpieces onto the worktable, wherein the second workpiece is arranged with respect to a first so that a thinner region of one of them overlaps a thicker region of the other; e. the second workpiece being placed on the worktable in the same spacial orientation with the vertical axis of the worktable as was the first workpiece when it was placed thereon; f. rotating the worktable through the same predetermined angular increment solely about its vertical axis as before; g. placing a third of the workpieces onto the worktable wherein the third workpiece is arranged with respect to the second so that a thinner region of one of the latter of the two workpieces overlaps a thicker region of the other; h. the third workpiece being placed on the worktable in the same spacial orientation with the vertical axis of the worktable as were the first and second workpieces when they were respectively placed on the worktable; i. rotating the worktable through The same predetermined angular increment solely about its vertical axis as before; j. repeating the steps with subsequent workpieces; and k. individually moving the worktable carrying the stable stack to a feeding station.
 6. A method for forming a stable stack from a plurality of identical limp material workpieces wherein the identity of the individual workpieces as well as the identity of the stack itself is preserved, such method comprising the steps of: a. positionally registering an individually transportable worktable and a stacking station relative to one another; b. placing a first of the pieces onto the worktable; c. moving the worktable and a stacking station in relation to one another through a predetermined angular increment solely about the vertical axis of the worktable; d. placing a second of the workpieces onto the worktable wherein the second workpiece is arranged in partial overlapping relationship with the first workpiece; e. moving the table and stacking station in relation to one another through the same predetermined angular increment solely about the vertical axis of the worktable; f. placing a third of the workpieces onto the worktable wherein the third workpiece is placed in partial overlapping relationship with the second workpiece; g. repeating the steps for subsequent workpieces to provide a stable stack in which the workpieces are arranged in partial overlapping and interlacing relationship to provide mutuality of support for the workpieces and thereby provide a stable stack; and h. individually displacing the worktable carrying the stable stack relative to the stacking station so that the worktable is situated at another station,
 7. The method for forming a stable stack of limp workpieces as claimed in claim 6 in which; i. the respective workpieces are placed onto the worktable in offset relationship with respect to the axis of the worktable; and j. the predetermined angular increment through which the worktable and feeding station are moved in relation to one another provides a fan stacking relationship.
 8. A system for use in the manufacture of garments, wearing apparel, headgear, footwear, home furnishings, and the like, in which a plurality of identical workpieces of limp material are utilized comprising: a. an individually transportable worktable for carrying a stack of the workpieces; b. a worktable support for individually engaging the worktable to support it; c. indexing drive means for indexing the worktable through a sequence of predetermined angular increments solely about a vertical axis passing through the worktable; d. delivery means for delivering the workpieces; e. pickup means for placing the respective workpieces onto the worktable in the same predetermined orientation with respect to the vertical axis preceding each indexing movement of the worktable to generate a stack of overlapping, interlaced workpieces; f. means for individually moving the worktable from one location to another.
 9. A system as claimed in claim 8 in which: g. the pickup means places the respective workpieces onto the worktable at a location offset from the vertical axis; and h. the indexing drive means rotates the worktable by an angular increment to generate a fan stack in which each of the workpieces partially overlaps its predecessor.
 10. A system as claimed in claim 8 in which: g. pickup means is provided for feeding successively the top workpieces individually from the stack of overlapping, interlaced workpieces. 